Вычислите: 1) 2целых2/5-(1/4+7/10); 2)3-(1/6+2/3); 3)7-(2целых3/4+7/12).

1) 2 2/5 - (1/4 + 7/10) = 48/20 - 5/20 - 14/20 = 29/20

2) 3 - (1/6 + 2/3) = 3 - (1/6 + 4/6) = 3 - 5/6 = 2 1/6

3) 7 - (2 3/4 + 7/12) = 7 - (2 9/12 + 7/12) = 7 - 2 16/12 =
                                = 6 12/12 - 3 4/12 = 3 8/12 = 3 2/3